The present invention relates generally to cast structural members, and particularly to concrete members having at least one roughened surface giving the appearance of a fracture. Depending upon the intended use of the members, such a fractured appearance may provide either an aesthetic appearance, provide structural advantages or both. Reference shall be made herein to the casting of concrete members although it is contemplated that the process is applicable to other casting materials as well.
In the past, members have been made of concrete with a roughened or fractured surface by actually mechanically fracturing the concrete after it has set. This has frequently been done by driving wedges or the like into the cast concrete and actually splitting it. The difficulty is that cast concrete is amorphous in structure and provides no actual fracture lines or cleavage planes with the result that it is difficult to create a member with a fractured surface if the member is particularly large in surface area and, in addition, it is difficult to predict the thickness of the finished structure inasmuch as it cannot be definitely determined where the fracture will occur.